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<FONT color="green">001</FONT>    package gates;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    /**<a name="line.3"></a>
<FONT color="green">004</FONT>     * A representation of the S gate defined in &lt;a href="http://arxiv.org/abs/quant-ph/0301079"&gt;Grover's Algorithm: Quantum Database Search&lt;/a&gt;<a name="line.4"></a>
<FONT color="green">005</FONT>     * Since this is just a phaseshift gate, wrap a phaseshift gate in a composite<a name="line.5"></a>
<FONT color="green">006</FONT>     * @author Alex Bush<a name="line.6"></a>
<FONT color="green">007</FONT>     *<a name="line.7"></a>
<FONT color="green">008</FONT>     */<a name="line.8"></a>
<FONT color="green">009</FONT>    public class SEnclosing extends CompositeGate {<a name="line.9"></a>
<FONT color="green">010</FONT>            <a name="line.10"></a>
<FONT color="green">011</FONT>            /**<a name="line.11"></a>
<FONT color="green">012</FONT>             * Private constructor to construct a S gate.<a name="line.12"></a>
<FONT color="green">013</FONT>             * @param target Target qubit for register to act on<a name="line.13"></a>
<FONT color="green">014</FONT>             */<a name="line.14"></a>
<FONT color="green">015</FONT>            protected SEnclosing(int target){<a name="line.15"></a>
<FONT color="green">016</FONT>                    super(createGate(target));<a name="line.16"></a>
<FONT color="green">017</FONT>            }<a name="line.17"></a>
<FONT color="green">018</FONT>            <a name="line.18"></a>
<FONT color="green">019</FONT>            /**<a name="line.19"></a>
<FONT color="green">020</FONT>             * Private method to create the appropriate phaseshift gate. For S this is Pi/2<a name="line.20"></a>
<FONT color="green">021</FONT>             */<a name="line.21"></a>
<FONT color="green">022</FONT>            private static Gate[] createGate(int target){<a name="line.22"></a>
<FONT color="green">023</FONT>                    Gate[] phase = {Factory.createPhaseShift(target, Math.PI/2.0)};<a name="line.23"></a>
<FONT color="green">024</FONT>                    return phase;<a name="line.24"></a>
<FONT color="green">025</FONT>            }<a name="line.25"></a>
<FONT color="green">026</FONT>    <a name="line.26"></a>
<FONT color="green">027</FONT>    }<a name="line.27"></a>




























































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